Just purchased the 3650 from AT#T.
Phone works great. After MANY attempts to connect to an ISP via GSM at 14.4k unsuccessfully I found out the following about AT#T:
😮 AT#T has disabled users of their network from connecting at 14.4k via GSM - forcing us to only use GPR$. I returned the 3650 to AT#T for a full refund.
Now online with GSM at 14.4k via a Tmobile 3650!